vendredi 15 août 2014

A new image of comet 67P/Churyumov-Gerasimenko shows the diversity of surface structures on the comet's nucleus. It was taken by the Rosetta spacecraft's OSIRIS narrow-angle camera on August 7, 2014. At the time, the spacecraft was 65 miles (104 kilometers) away from the 2.5-mile-wide (4-kilometer) nucleus.

In the image, the comet’s head (in the top half of the image) exhibits parallel linear features that resemble cliffs, and its neck displays scattered boulders on a relatively smooth, slumping surface. In comparison, the comet's body (lower half of the image) seems to exhibit a multi-variable terrain with peaks and valleys, and both smooth and rough topographic features.

Launched in March 2004, Rosetta was reactivated in January 2014 after a record 957 days in hibernation. Composed of an orbiter and lander, Rosetta's objectives are to study comet 67P/Churyumov-Gerasimenko up close in unprecedented detail, prepare for landing a probe on the comet's nucleus in November, and track its changes as it sweeps past the sun.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander will obtain the first images taken from a comet's surface and will provide the first analysis of a comet's composition by drilling into the surface. Rosetta also will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system, and the role comets may have played in seeding Earth with water.

The scientific imaging system, OSIRIS, was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with Center of Studies and Activities for Space, University of Padua (Italy), the Astrophysical Laboratory of Marseille (France), the Institute of Astrophysics of Andalusia, CSIC (Spain), the Scientific Support Office of the European Space Agency (Netherlands), the National Institute for Aerospace Technology (Spain), the Technical University of Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden) and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain, and Sweden and the ESA Technical Directorate.

Illustration above: Rosetta orbiting comet 67P (photo-montage by Orbiter.ch Aerospace, the distance and sizes between the comet and the probe are not realistic) original images credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta's Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. JPL, a division of the California Institute of Technology, Pasadena, manages the U.S. participation in the Rosetta mission for NASA's Science Mission Directorate in Washington.

Image above: In this image from NASA's Curiosity Mars rover looking up the ramp at the northeastern end of "Hidden Valley," a pale outcrop including drilling target "Bonanza King" is at the center of the scene. The rover's Navcam captured this northward view on Aug. 4, 2014, from the valley's sandy floor. Image Credit: NASA/JPL-Caltech.

The team operating NASA's Curiosity Mars rover has chosen a rock that looks like a pale paving stone as the mission's fourth drilling target, if it passes engineers' evaluation.

They call it "Bonanza King."

It is not at the "Pahrump Hills" site the team anticipated the rover might reach by mid-August. Unexpected challenges while driving in sand prompted the mission to reverse course last week after entering a valley where ripples of sand fill the floor and extend onto sloping margins. However, the new target outcrop's brightness and its position within the area's geological layers resemble the Pahrump Hills outcrop.

"Geologically speaking, we can tie the Bonanza King rocks to those at Pahrump Hills. Studying them here will give us a head start in understanding how they fit into the bigger picture of Gale Crater and Mount Sharp," said Curiosity Deputy Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory in Pasadena, California.

Image above: This image from NASA's Curiosity Mars rover looks down the ramp at the northeastern end of "Hidden Valley" and across the sandy-floored valley to lower slopes of Mount Sharp on the horizon. The rover's Navigation Camera captured this southward view on Aug. 12, 2014, after exiting the valley. Image Credit: NASA/JPL-Caltech.

Mount Sharp is the mission's long-term science destination, offering a stack of layers holding evidence about environmental changes on ancient Mars. The mountain rises from inside Gale Crater, where Curiosity landed in August 2012. All three rocks the rover has drilled so far have been geologically associated with the crater floor, rather than the mountain. Sample material pulled from the first two and delivered to Curiosity's onboard analytical laboratories in 2013 provided evidence for ancient environmental conditions favorable for microbial life. A drilled sample from Bonanza King may add understanding about how environments varied and evolved.

"This rock has an appearance quite different from the sandstones we've been driving through for several months," Vasavada said. "The landscape is changing, and that's worth checking out."

It lies in one of several patches of similar-looking slabs, up to about the size of dinner plates, on the ramp at the northeastern end of sandy-floored "Hidden Valley." Curiosity passed over them early last week when it entered the valley, headed toward Pahrump Hills and, beyond that, toward the planned entry point to Mount Sharp's slopes.

The rover's wheels slipped more in Hidden Valley's sand than the team had expected based on experience with one of the mission's test rovers driven on sand dunes in California. The valley is about the length of a football field and does not offer any navigable exits other than at the northeastern and southwestern ends.

Image above: The pale rocks in the foreground of this Aug. 14, 2014, image from NASA's Curiosity Mars rover include the "Bonanza King" target under consideration to become the fourth rock drilled by the rover. The view from Curiosity's front Hazcam faces southward down a ramp into sandy-floored "Hidden Valley." Image Credit: NASA/JPL-Caltech.

"We need to gain a better understanding of the interaction between the wheels and Martian sand ripples, and Hidden Valley is not a good location for experimenting," said Curiosity Project Manager Jim Erickson of JPL.

Terrain with sharp rocks that Curiosity has previously navigated tore holes in the rover's wheels. Sandy terrain could still be part of the rover's route to Mount Sharp. Compared to sharp-rock terrain, sandy ground could reduce the pace of wheel damage. In some sandy areas, ripples don't cover the ground deeply wall-to-wall, as they do in Hidden Valley.

Curiosity reversed course and drove out of Hidden Valley northeastward. On the way toward gaining a good viewpoint to assess a possible alternative route north of the valley, it passed over the pale paving stones on the ramp again. Where a rover wheel cracked one of the rocks, it exposed bright interior material, possibly from mineral veins.

Image above: This Aug. 14, 2012, image from the Mastcam on NASA's Curiosity Mars rover shows an outcrop that includes the "Bonanza King" rock under consideration as a drilling target. Raised ridges on the flat rocks are visible at right. Tread marks from a rover wheel are in the lower half. Image Credit: NASA/JPL-Caltech/MSSS.

This summer, Curiosity's team has developed a plan for compressing the multi-day schedule of rover activities involved in collecting a drilled rock sample and delivering the sample for onboard analysis. This "condensed drilling" plan requires adjustment of staffing levels for several days, due to the complexity of the rover activities involved. The needed staffing had been slated for mid-August in anticipation of getting to Pahrump Hills.

"We considered postponing the first condensed drilling, and we considered other possible drilling targets, but this outcrop on the ramp is too appealing to pass up," Vasavada said.

One step in assessing whether Bonanza King can be drilled will be to check whether the individual plates of the outcrop are loose. During the drilling campaign, the team will also be analyzing possible routes to Mount Sharp and planning how to better understand how the rover's wheels interact with Martian sand ripples.

JPL, a division of Caltech, built Curiosity and manages Mars rover projects for NASA's Science Mission Directorate in Washington.

Orbital Sciences Cygnus commercial cargo craft completed a month-long delivery mission to the International Space Station Friday when it was released from the grips of the Canadarm2 robotic arm at 6:40 a.m. EDT. Cygnus is now orbiting on its own, separating from the station and heading for a deorbit and a fiery entry over the Pacific Ocean on Sunday.

ISS Cygnus CRS-2 Departs from International Space Station

Expedition 40 Flight Engineers Alexander Gerst and Reid Wiseman were inside the cupola remotely controlling the 58-foot Canadian robotic arm from the robotics workstation. Gerst, who was backed up by Wiseman, was in charge of releasing the resupply vehicle after ground controllers at Mission Control, Houston remotely maneuvered it into the release position following its unberthing from the Earth-facing port of the Harmony module.

Filled with trash, Cygnus completed its second commercial resupply mission for NASA. Orbital Sciences launched their spacecraft July 13 atop an Antares rocket from the Mid-Atlantic Regional Spaceport at the Wallops Flight Facility, Virginia on a three-day journey to the orbital laboratory. At least eight more missions will be flown by Cygnus to the station through 2016.

Cygnus delivered nearly 3,300 pounds of science, supplies and spacewalking gear when it was captured and berthed to Harmony July 16. Aboard the spacecraft were items such as food, life support equipment, thermal control hardware and photography and video gear.

Experiment hardware was also on the Cygnus manifest ensuring the continuous international research aboard the orbital laboratory.

Image above: The Cygnus is in the grips of Canadarm2 moments before being released in Feb. 18, 2014 during Expedition 38.

A flock of nanosatellites was also shipped to the station aboard Cygnus for future release from the Kibo laboratory module’s airlock beginning next week. Individually known as “Dove” satellites, the group will collect continuous Earth imagery documenting natural and man-made conditions of the environment to improve disaster relief and increase agricultural yields.

Hardware upgrades were brought up to the station on the ship for a trio of tiny satellites that float inside the station known as SPHERES (Synchronized Position Hold, Engage, Reorient, Experimental Satellites). Gear enabling studies for educators, students and private researchers was also delivered for the NanoRacks program in a partnership with NASA under the Space Act Agreement.

The Expedition 40 crewmembers hope to document Cygnus’ reentry Sunday as part of an engineering exercise to study the mechanics of the breakup of a space vehicle. Cygnus is scheduled to deorbit Sunday around 8:30 a.m. EDT.

Orbit correction took place in the normal mode. According to the telemetry propulsion cargo vehicle ATV-5 was performed at 20 hours 58 minutes Moscow time. Duration of its operation was 469.4 seconds. As a result, ISS has received the increment speed of 1.1 m/sec., Orbit height increased by 2 km.

The average height of the ISS orbit is now 416.4 km.

ISS reboost by ESA's ATV (Automated Transfer Vehicle)

Reboost performed in order to create the conditions for landing in a predetermined area of the vehicle crew manned spacecraft Soyuz TMA-12M as part of the Russian Space Agency cosmonauts Alexander Skvortsov, Oleg Artemyev and NASA astronaut Steven Swanson. The crew will return to Earth September 11, 2014.

jeudi 14 août 2014

New data from NASA’s Chandra X-ray Observatory offer a glimpse into the environment of a star before it exploded earlier this year, and insight into what triggered one of the closest supernovas witnessed in decades.

The data gathered on the Jan. 21 explosion, a Type Ia supernova, allowed scientists to rule out one possible cause. These supernovas may be triggered when a white dwarf takes on too much mass from its companion star, immersing it in a cloud of gas that produces a significant source of X-rays after the explosion.

Astronomers used NASA's Swift and Chandra telescopes to search the nearby Messier 82 galaxy, the location of the explosion, for such an X-ray source. However, no source was found, revealing the region around the site of the supernova is relatively devoid of material.

“While it may sound a bit odd, we actually learned a great deal about this supernova by detecting absolutely nothing,” said Raffaella Margutti of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, who led the study. “Now we can essentially rule out that the explosion was caused by a white dwarf continuously pulling material from a companion star.”

This supernova, SN 2014J, could instead have been caused by the merger of two white dwarf stars, an event that should result in little or no X-rays after the explosion. Further observations could rule out or confirm other possible triggers.

“Being able to eliminate one of the main possible explanations for what caused SN 2014J to explode is a big step,” said CfA’s Atish Kamble, a co-author of the study. “The next step is to narrow things down even further.”

Type Ia supernovas are used as cosmic distance-markers, and have played a key role in the discovery of the universe’s accelerated expansion. At about 12 million light-years from Earth, SN 2014J and its host galaxy are close -- from a cosmic perspective. This offers scientists a chance to observe details that would be too hard to detect in more distant supernovas.

Image above: NASA’s Chandra X-ray Observatory is helping determine what caused SN 2014J, one of the closest supernovas discovered in decades. By comparing X-ray data taken before and after the stellar explosion, scientists can learn more about what set it off. Image Credit: NASA/SAO/CXC/R. Margutti et al.

“It’s crucial that we understand exactly how these stars explode because so much is riding on our observations of them for cosmology,” said co-author Jerod Parrent also from CfA. “SN 2014J might be a chance of a lifetime to study one of these supernovas in detail as it happens.”

The study of SN 2014J is similar to a study led by Margutti about another supernova, SN 2011fe, in the nearby galaxy M101.

This study was conducted by CfA’s Supernova Forensics Team, led by Alicia Soderberg. The results were published online and in the July 20 print issue of The Astrophysical Journal.

Seven rare, microscopic interstellar dust particles that date to the beginnings of the solar system are among the samples collected by scientists who have been studying the payload from NASA's Stardust spacecraft since its return to Earth in 2006. If confirmed, these particles would be the first samples of contemporary interstellar dust.

A team of scientists has been combing through the spacecraft's aerogel and aluminum foil dust collectors since Stardust returned in 2006.The seven particles probably came from outside our solar system, perhaps created in a supernova explosion millions of years ago and altered by exposure to the extreme space environment.

The research report appears in the Aug. 15 issue of the journal Science. Twelve other papers about the particles will appear next week in the journal Meteoritics & Planetary Science.

Image above: The largest interstellar dust track found in the Stardust aerogel collectors was this 35 micron-long hole produced by a 3 picogram mote that was probably traveling so fast that it vaporized upon impact. The other two likely interstellar dust grains were traveling more slowly and remained intact after a soft landing in the aerogel. Image Credit: Andrew Westphal, UC Berkeley.

"These are the most challenging objects we will ever have in the lab for study, and it is a triumph that we have made as much progress in their analysis as we have," said Michael Zolensky, curator of the Stardust laboratory at NASA’s Johnson Space Center in Houston and coauthor of the Science paper.

Stardust was launched in 1999 and returned to Earth on Jan. 15, 2006, at the Utah Test and Training Range, 80 miles west of Salt Lake City. The Stardust Sample Return Canister was transported to a curatorial facility at Johnson where the Stardust collectors remain preserved and protected for scientific study.

Inside the canister, a tennis racket-like sample collector tray captured the particles in silica aerogel as the spacecraft flew within 149 miles of a comet in January 2004. An opposite side of the tray holds interstellar dust particles captured by the spacecraft during its seven-year, three-billion-mile journey.

Scientists caution that additional tests must be done before they can say definitively that these are pieces of debris from interstellar space. But if they are, the particles could help explain the origin and evolution of interstellar dust.

The particles are much more diverse in terms of chemical composition and structure than scientists expected. The smaller particles differ greatly from the larger ones and appear to have varying histories. Many of the larger particles have been described as having a fluffy structure, similar to a snowflake.

Two particles, each only about two microns (thousandths of a millimeter) in diameter, were isolated after their tracks were discovered by a group of citizen scientists. These volunteers, who call themselves "Dusters," scanned more than a million images as part of a University of California, Berkeley, citizen-science project, which proved critical to finding these needles in a haystack.

Image above: The largest interstellar dust track found in the Stardust aerogel collectors was this 35 micron-long hole produced by a 3 picogram speck of dust that was probably traveling so fast that it vaporized upon impact. The other two likely interstellar dust grains were traveling more slowly and remained in. Image Credit: UC Berkeley/Andrew Westphal.

A third track, following the direction of the wind during flight, was left by a particle that apparently was moving so fast -- more than 10 miles per second (15 kilometers per second) -- that it vaporized. Volunteers identified tracks left by another 29 particles that were determined to have been kicked out of the spacecraft into the collectors.

Four of the particles reported in Science were found in aluminum foils between tiles on the collector tray. Although the foils were not originally planned as dust collection surfaces, an international team led by physicist Rhonda Stroud of the Naval Research Laboratory searched the foils and identified four pits lined with material composed of elements that fit the profile of interstellar dust particles.

Three of these four particles, just a few tenths of a micron across, contained sulfur compounds, which some astronomers have argued do not occur in interstellar dust. A preliminary examination team plans to continue analysis of the remaining 95 percent of the foils to possibly find enough particles to understand the variety and origins of interstellar dust.

Supernovas, red giants and other evolved stars produce interstellar dust and generate heavy elements like carbon, nitrogen and oxygen necessary for life. Two particles, dubbed Orion and Hylabrook, will undergo further tests to determine their oxygen isotope quantities, which could provide even stronger evidence for their extrasolar origin.

Stardust Next spacecraft. Image Credit: NASA / JPL-Caltech

Scientists at Johnson have scanned half the panels at various depths and turned these scans into movies, which were then posted online, where the Dusters could access the footage to search for particle tracks.

Once several Dusters tag a likely track, Andrew Westphal, lead author of the Science article, and his team verify the identifications. In the one million frames scanned so far, each a half-millimeter square, Dusters have found 69 tracks, while Westphal has found two. Thirty-one of these were extracted along with surrounding aerogel by scientists at Johnson and shipped to UC Berkeley to be analyzed.

Video above: Crews at NASA Goddard’s Wallops Flight Facility are hard at work integrating a suite of instruments into a C-130 aircraft in preparation for the start of the ARISE campaign later this month. ARISE, which stands for Arctic Radiation IceBridge Sea and Ice Experiment, will make simultaneous measurements of ice, clouds and levels of incoming and outgoing radiation, the balance of which determines the degree of climate warming. Video credit: NASA Goddard Space Flight Center.

A new NASA field campaign will begin flights over the Arctic this summer to study the effect of sea ice retreat on Arctic climate. The Arctic Radiation IceBridge Sea and Ice Experiment (ARISE) will conduct research flights Aug. 28 through Oct. 1, covering the peak of summer sea ice melt.

ARISE is NASA's first Arctic airborne campaign designed to take simultaneous measurements of ice, clouds and the levels of incoming and outgoing radiation, the balance of which determines the degree of climate warming. The campaign team will fly aboard NASA’s C-130 aircraft from Thule Air Base in northern Greenland the first week and from Eielson Air Force Base near Fairbanks, Alaska, through the remainder of the campaign.

In recent years the Arctic has experienced increased summer sea ice loss. Scientists expect the exposure of more open water to sunlight could enhance warming in the region and cause the release of more moisture to the atmosphere. Additional moisture could affect cloud formation and the exchange of heat from Earth’s surface to space. Researchers are grappling with how these changes in the Arctic affect global climate.

"A wild card in what's happening in the Arctic is clouds and how changes in clouds, due to changing sea-ice conditions, enhance or offset warming," said Bill Smith, ARISE principal investigator at NASA's Langley Research Center in Hampton, Virginia.

ARISE was planned over the last year to take advantage of NASA’s existing capabilities for gathering data about ongoing changes in the Arctic. Satellites provided some information about clouds and the energy balance in the Arctic, but the multiple instruments flown during ARISE should provide further insight.

"The clouds and surface conditions over the Arctic as we observe them from satellites are very complex," Smith said. "We need more information to understand how to better interpret the satellite measurements, and an aircraft can help with that."

The array of instruments on ARISE should help scientists better observe how sea ice loss is affecting Arctic cloud formation and therefore the balance of incoming and outgoing radiation. Low-level clouds typically reflect more sunlight and offset warming, while higher clouds are typically less reflective and act to trap more heat in the atmosphere.

“It’s a complex business, but it depends on a lot of things we can, in fact, measure,” said Hal Maring, program manager for radiation sciences in the Earth Science Division at NASA Headquarters in Washington.

ARISE researchers will fly survey missions that target different cloud types and surface conditions, such as open water, land ice and sea ice. The missions will be timed to fly under the orbit paths of key satellite instruments, such as the Clouds and the Earth’s Radiant Energy Systems (CERES) instruments on multiple NASA satellites. Each morning, mission planners will look at satellite timings and weather forecasts to design flight plans that meet the most objectives of the campaign.

The NASA C-130, based at the Wallops Flight Facility in Virginia, will carry instruments that measure solar (incoming) and infrared (outgoing) radiation, ice surface elevation and cloud properties such as cloud particle size. This will be the first time that many of these instruments, including the mission's laser altimeter, have flown together.

The ARISE campaign is a joint effort of the Radiation Sciences, Cryospheric Sciences and Airborne Sciences programs of the Earth Science Division in NASA's Science Mission Directorate in Washington.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

Image above: The SeaWinds scatterometer on NASA's QuikScat satellite stares into the eye of 1999's Hurricane Floyd as it hits the U.S. coast. The arrows indicate wind direction, while the colors represent wind speed, with orange and yellow being the fastest. NASA/JPL-Caltech.

The ocean covers 71 percent of Earth's surface and affects weather over the entire globe. Hurricanes and storms that begin far out over the ocean affect people on land and interfere with shipping at sea. And the ocean stores carbon and heat, which are transported from the ocean to the air and back, allowing for photosynthesis and affecting Earth's climate. To understand all these processes, scientists need information about winds near the ocean's surface.

NASA's ISS-RapidScat, launching to the International Space Station this fall, will watch those winds with a tried and true instrument called a scatterometer. Since satellite scatterometers began collecting data in the 1970s, their soundings have become essential to our understanding of Earth's ocean winds.

NASA's ISS-RapidScat on the International Space Station

Scatterometers send microwave pulses to Earth's surface at an angle. A smooth ocean surface reflects most of the energy like a mirror, away from the satellite, but strong waves scatter some of the signal back toward the spacecraft. From the strength of this backscatter, scientists can estimate the speed and direction of wind at the ocean's surface.

"Before scatterometers, we could only measure ocean winds on ships, and sampling from ships is very limited," said Timothy Liu of NASA's Jet Propulsion Laboratory in Pasadena, California, who led the science team for NASA's QuikScat mission.

Scatterometry began to emerge during World War II, when scientists realized wind disturbing the ocean's surface caused noise in their radar signals. NASA included an experimental scatterometer in its first space station in 1973 and again when it launched its SeaSat satellite in 1978. During its three-month life, SeaSat's scatterometer provided scientists with more individual wind observations than ships had collected in the previous century.

A JPL team then designed a mission called NSCAT, the NASA Scatterometer. When the Japanese spacecraft carrying NSCAT failed in 1997, engineers rushed to complete JPL's SeaWinds scatterometer instrument, already in development. In just a year, JPL engineers finished the SeaWinds scatterometer, and Ball Aerospace & Technologies Corporation created a satellite from another project's leftover parts. NASA named the expedited mission "QuikScat."

"We had to build the SeaWinds instrument using spare parts and do it very fast," Liu said. "It was only meant to be a gap-filler. But then it lasted for 10 years."

From 1999 until 2009, QuikScat collected 400,000 measurements over 90 percent of Earth's surface daily. Researchers used the data to improve weather forecasts, monitor typhoons and hurricanes, design shipping routes and place ocean fisheries. Scientists also found that SeaWinds could measure snow cover, identify icebergs floating near Antarctica and track the shrinking of the Amazon rainforest.

The number of scatterometers in space grew drastically during QuikScat's decade. "It used to be, we were the only game in town. Now there's an international array of scatterometers up there," Liu said.

QuikScat provided its full range of data until its antenna stopped spinning in 2009, significantly reducing the amount of Earth's surface it measured. But the data it continues to collect are now used to calibrate measurements from other satellites.

"We tipped QuikScat slightly so it was at the same angle as the Indian scatterometer, OSCAT, and continued to do that throughout the whole OSCAT mission," said JPL's Phil Callahan, the data products manager for QuikScat. Cross-calibrating new instruments like OSCAT with existing ones ensures that the new data can be combined seamlessly with the old, allowing researchers to examine long-term trends.

When NASA's ISS-RapidScat mission begins collecting data this fall, it will add data to the same archive.

"OSCAT stopped working earlier this year, so RapidScat's presence is very important," said Howard Eisen, the RapidScat project manager at JPL. "We can transfer the calibration standard from QuikScat to RapidScat, which can then pass it on to future scatterometers, making a continuous, 15-plus year record."

As with QuikScat, JPL engineers built RapidScat in less than two years. The mission combines new industrial-grade hardware and older inherited hardware used to develop and test QuikScat, and was developed for just $26 million. QuikScat will calibrate the new mission as well.

Also as with QuikScat, RapidScat is meant to be a "gap-filler" on its two-year mission. Another scatterometer from the Indian Space Research Organization is scheduled to join RapidScat in orbit in the next two years. RapidScat will be the last scatterometer built from SeaWinds materials, but likely not the last in a growing record of Earth's winds over the ocean.

"Including RapidScat, we've gotten three scatterometers and more than 10 years of data from the SeaWinds project," Callahan said.

ISS-RapidScat is one of five new NASA missions launching in 2014. NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

A commercial satellite, WorldView 3, was successfully launched today, August 13th 2014 at 18:30 UTC from Vandenberg Air Force Base in California on a Atlas V 401 rocket.

This was the 48th launch of an Atlas V rocket. WorldView 3 is an Earth imaging satellite with an ability to see an object as small as 31cm for the American company Digital Globe. This will be the most powerful commercial Earth imaging satellite in orbit.

Launch of WorldView 3 on Atlas V 401 from Vandenberg

WorldView-3 will enhance Digital Globe’s industry-leading constellation and will further support customers across a variety of industries, such as agriculture, mining, and oil and gas. For more information about the WorldView-3 satellite, visit http://worldview3.digitalglobe.com/.

WorldView-3 satellite

WorldView-3 will be the 10th of 15 planned missions ULA is slated to launch in 2014, and ULA's 86th since the company formed in 2006.

mercredi 13 août 2014

Those who enjoy the spectacle of the Perseids, Geminids or other annual meteor showers likely aren’t thinking about where these shooting stars originated or whether they might pose a danger. Scientists, however, think about such things and will use the vantage point of a special window on the International Space Station to learn more about the composition and behavior of meteors and their parent bodies. The Meteor investigation will help scientists better understand the asteroids and comets crossing Earth’s orbit and how these celestial objects have affected our planet. It also could help protect spacecraft and Earth from potential collisions with this celestial debris.

The investigation, which will launch to the station on Orbital Sciences' third commercial resupply flight, will spend two years recording meteor showers using a special camera installed in the station’s Window Observational Research Facility (WORF). The camera is programmed to record predictable showers, and its continuous measurement of meteor interactions with Earth’s atmosphere could spot unpredicted ones as well.

Space-based viewing of meteor showers offers many advantages over traditional observation by ground- or aircraft-based instruments. Viewing from the station is not affected by weather or interference from Earth’s atmosphere. Instruments on Earth are also limited to short periods of observation time and viewing field, but the camera aboard the station will record for roughly 560 minutes every day. That is the amount of time the station is in darkness as it orbits Earth 16 times a day.

Partners in the Meteor investigation include the Center for the Advancement of Science in Space (CASIS), Southwest Research Institute (SwRI) in San Antonio and Japan’s Planetary Exploration Research Center (PERC) at Chiba Institute of Technology.

Once installed, the Meteor system will operate mostly on its own. Michael Fortenberry, principal investigator for Meteor and an engineer with SwRI, explains that the crew will only need to adjust the lens focus and change out hard drives that store high-resolution video collected by the camera. A software program will identify and separate video clips that likely include meteors, and those can be further analyzed later on the ground. Scientists can use these images to glean information such as the size of a particle of meteoric dust based on its flight path and light curve.

Going beyond identifying meteors and monitoring their activity, the instrument has the additional capability to help classify their chemical composition. A device on the camera called a diffraction grating separates light passing through it into different wavelengths or colors, known as spectra, just as a prism does. The device will record spectra of light emitted for specific meteoroids, which investigators can use to determine the abundance of several elements in the meteoroids or meteor dust.

“From previous observation on the ground, we already know the parent body for these meteors,” explains Meteor co-investigator Tomoko Arai, Ph.D., a staff scientist at PERC. “The spectral information will tell us more about these parent bodies and help us understand their materials.”

The camera is scheduled to record all 12 known major showers. Secondary targets include minor meteor showers and periods with little or no identified regular activity. Observation of de-orbiting spacecraft and other targets also will be made. “There is a chance we could find new minor meteor showers, or observe meteors from an unexpected source like Comet Ison,” says Fortenberry.

Image above: A Perseid meteor streaks through the Earth's atmosphere, as seen and photographed by astronaut Ron Garan while aboard the International Space Station on August 13, 2011. Image Credit: NASA.

Meteors are created by the disintegration of comets or asteroids orbiting the sun. Those that enter Earth's atmosphere heat up and burn, causing the visible streak we see during a shower. Although the exact number of meteors entering the atmosphere varies during each event, some major showers can produce a peak of more than 100 visible meteors per hour.

Some meteor-producing bodies have the potential to create meteors so large that they do not burn up completely on their trip through Earth’s atmosphere and actually strike the surface. This investigation will collect much more data than was previously possible about what already hits our planet. This data will be correlated with information from other sensors and analysis to determine how many meteors are entering the atmosphere and their characteristics. Those characteristics will help scientists better understand which parent bodies might create meteors that pose a threat to Earth, along with their physical and chemical makeup. In addition, data on orbital debris, both natural and man-made, can be used to time and position spacecraft to keep them safe from collisions in space.

The WORF provides a stable platform for hand-held photography and other research activities at the U.S. Laboratory Science Window, the highest optical-quality window ever installed on a human space vehicle. The Window enables the use of high-resolution cameras from inside the station rather than outside, where instruments are subject to the vacuum and extreme temperatures of space.

The Meteor investigation adds to other monitoring of meteors on orbit, such as through Crew Earth Observations (CEO). So the next time you enjoy a meteor shower, rest easy knowing that these scientists are keeping an eye on things.

A track about one-third of a mile (500 meters) long on Mars shows where an irregularly shaped boulder careened downhill to its current upright position, seen in a July 3, 2014, image from the High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA's Mars Reconnaissance Orbiter.

Image above: The track left by an oblong boulder as it tumbled down a slope on Mars runs from upper left to right center of this image. The boulder came to rest in an upright attitude at the downhill end of the track. The HiRISE camera on NASA's Mars Reconnaissance Orbiter recorded this view on July 14, 2014. Image Credit: NASA/JPL-Caltech/Univ. of Arizona.

The shadow cast by the rock in mid-afternoon sunlight reveals it is about 20 feet (6 meters) tall. In the downward-looking image, the boulder is only about 11.5 feet (3.5 meters) wide. It happened to come to rest with its long dimension vertical. The trail it left on the slope has a pattern that suggests the boulder couldn't roll smoothly or straight due to its shape.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate in Washington. HiRISE, one of six science instruments on the orbiter, is operated by the University of Arizona, Tucson. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colorado.

For more information about the Mars Reconnaissance Orbiter, which has been studying Mars from orbit since 2006, visit: http://www.nasa.gov/mro

August 14, 2014 at 20:58 Moscow time planned for orbit correction of the International Space Station.

Correction is carried out to create the conditions for landing in a predetermined area of the vehicle crew manned spacecraft "Soyuz TMA-12M" as part of the Russian Space Agency cosmonauts Alexander Skvortsov, Oleg Artemyev and NASA astronaut Steven Swanson. The crew will return to Earth September 11, 2014.

NASA's Cassini spacecraft recently captured images of clouds moving across the northern hydrocarbon seas of Saturn's moon Titan. This renewed weather activity, considered overdue by researchers, could finally signal the onset of summer storms that atmospheric models have long predicted.

The Cassini spacecraft obtained the new views in late July, as it receded from Titan after a close flyby. Cassini tracked the system of clouds developing and dissipating over the large methane sea known as Ligeia Mare for more than two days. Measurements of cloud motions indicate wind speeds of around 7 to 10 mph (3 to 4.5 meters per second).

For several years after Cassini's 2004 arrival in the Saturn system, scientists frequently observed cloud activity near Titan's south pole, which was experiencing late summer at the time. Clouds continued to be observed as spring came to Titan's northern hemisphere. But since a huge storm swept across the icy moon's low latitudes in late 2010, only a few small clouds have been observed anywhere on the icy moon. The lack of cloud activity has surprised researchers, as computer simulations of Titan's atmospheric circulation predicted that clouds would increase in the north as summer approached, bringing increasingly warm temperatures to the atmosphere there.

"We're eager to find out if the clouds' appearance signals the beginning of summer weather patterns, or if it is an isolated occurrence," said Elizabeth Turtle, a Cassini imaging team associate at the Johns Hopkins University Applied Physics Lab in Laurel, Maryland. "Also, how are the clouds related to the seas? Did Cassini just happen catch them over the seas, or do they form there preferentially?"

A year on Titan lasts about 30 Earth years, with each season lasting about seven years. Observing seasonal changes on Titan will continue to be a major goal for the Cassini mission as summer comes to Titan's north and the southern latitudes fall into winter darkness.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team consists of scientists from the United States, England, France and Germany. The imaging team is based at the Space Science Institute in Boulder, Colorado.

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has captured an extreme and rare event in the regions immediately surrounding a supermassive black hole. A compact source of X-rays that sits near the black hole, called the corona, has moved closer to the black hole over a period of just days.

"The corona recently collapsed in toward the black hole, with the result that the black hole's intense gravity pulled all the light down onto its surrounding disk, where material is spiraling inward," said Michael Parker of the Institute of Astronomy in Cambridge, United Kingdom, lead author of a new paper on the findings appearing in the Monthly Notices of the Royal Astronomical Society.

Image above: The regions around supermassive black holes shine brightly in X-rays. Some of this radiation comes from a surrounding disk, and most comes from the corona, pictured here in this artist's concept as the white light at the base of a jet. This is one of a few possible shapes predicted for coronas. Image Credit: NASA/JPL-Caltech.

As the corona shifted closer to the black hole, the gravity of the black hole exerted a stronger tug on the X-rays emitted by it. The result was an extreme blurring and stretching of the X-ray light. Such events had been observed previously, but never to this degree and in such detail.

Supermassive black holes are thought to reside in the centers of all galaxies. Some are more massive and rotate faster than others. The black hole in this new study, referred to as Markarian 335, or Mrk 335, is about 324 million light-years from Earth in the direction of the Pegasus constellation. It is one of the most extreme of the systems for which the mass and spin rate have ever been measured. The black hole squeezes about 10 million times the mass of our sun into a region only 30 times the diameter of the sun, and it spins so rapidly that space and time are dragged around with it.

Even though some light falls into a supermassive black hole never to be seen again, other high-energy light emanates from both the corona and the surrounding accretion disk of superheated material. Though astronomers are uncertain of the shape and temperature of coronas, they know that they contain particles that move close to the speed of light.

NASA's Swift satellite has monitored Mrk 335 for years, and recently noted a dramatic change in its X-ray brightness. In what is called a target-of-opportunity observation, NuSTAR was redirected to take a look at high-energy X-rays from this source in the range of 3 to 79 kiloelectron volts. This particular energy range offers astronomers a detailed look at what is happening near the event horizon, the region around a black hole from which light can no longer escape gravity's grasp.

Follow-up observations indicate that the corona still is in this close configuration, months after it moved. Researchers don't know whether and when the corona will shift back. What is more, the NuSTAR observations reveal that the grip of the black hole's gravity pulled the corona's light onto the inner portion of its superheated disk, better illuminating it. Almost as if somebody had shone a flashlight for the astronomers, the shifting corona lit up the precise region they wanted to study.

The new data could ultimately help determine more about the mysterious nature of black hole coronas. In addition, the observations have provided better measurements of Mrk 335's furious relativistic spin rate. Relativistic speeds are those approaching the speed of light, as described by Albert Einstein's theory of relativity.

"We still don't understand exactly how the corona is produced or why it changes its shape, but we see it lighting up material around the black hole, enabling us to study the regions so close in that effects described by Einstein's theory of general relativity become prominent," said NuSTAR Principal Investigator Fiona Harrison of the California Institute of Technology (Caltech) in Pasadena. "NuSTAR's unprecedented capability for observing this and similar events allows us to study the most extreme light-bending effects of general relativity."

NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation in Dulles, Virginia. Its instrument was built by a consortium including Caltech, JPL, the University of California, Berkeley, Columbia University, New York, NASA's Goddard Space Flight Center, Greenbelt, Maryland, the Danish Technical University in Denmark, Lawrence Livermore National Laboratory in Livermore, California, ATK Aerospace Systems in Goleta, California, and with support from the Italian Space Agency (ASI) Science Data Center.

NuSTAR's mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located in Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Rohnert Park, California. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

mardi 12 août 2014

Who doesn’t love an upgrade? Newer, better and oh so shiny is great, but what’s really fantastic is when a change unlocks new possibilities. That’s the case with NASA’s fix-it investigation on the International Space Station, the Robotic Refueling Mission (RRM). The award-winning endeavor moved one step closer to its 2.0 update with the delivery of new RRM hardware aboard the European Automated Transfer Vehicle-5, which docked with the space station today. The RRM module, affixed to an exterior space station platform since 2011, now awaits the robotic transfer of two new task boards and a borescope inspection tool that will equip RRM for a new round of satellite-servicing demonstrations.

“The Robotic Refueling Mission is about to get a refresh, and we couldn’t be more excited,” explains Benjamin Reed, deputy project manager of the Satellite Servicing Capabilities Office, the team responsible for RRM’s development and operations on orbit.

Image above: View of the Robotic Refueling Mission (RRM) module outside of the International Space Station as photographed by an Expedition 28 crew member in 2011. Image Credit: NASA.

“This is the beauty of doing research on the space station. We’re not tied to the original hardware complement we sent up three years ago. The cadence of space station supply flights gives us the opportunity to swap equipment so we can tackle a new set of technology demonstrations.”

Since 2011, the duo of RRM and Dextre—the Canadian Space Agency robot that acts as a “handyman” for external station activities—has been steadily evaluating a set of NASA-developed, game-changing technologies that would enable remotely controlled robots to eventually repair and service spacecraft in orbit. The overarching challenge facing the NASA RRM team is devising and manufacturing new robotic, teleoperated tools and techniques to service spacecraft that were not designed for in-flight service.

Robotic refueling and the tasks accompanying it – including blanket cutting, wire cutting and cap and fastener removal – were the primary focus of RRM’s first set of technology demonstrations.

Image above: A new complement of hardware will outfit NASA’s Robotic Refueling Mission (center on International Space Station platform) for a fresh set of satellite-servicing demonstrations. Image Credit: NASA.

In its second phase of activities, RRM will move past its refueling roots to test out the inspection capabilities of a new space tool named VIPIR, the Visual Inspection Poseable Invertebrate Robot. The team will also tackle the intermediary steps leading toward spacecraft cryogen replenishment and host a demonstration of next-generation solar cell technology and a carbon nanotube experiment.

“The common thread is building up NASA’s collection of enabling satellite-servicing capabilities,” says Reed. “Every capability translates into another option a satellite owner could potentially choose to keep his or her satellite operating longer and performing optimally.”

Image above: A new RRM tool named VIPIR – the Visual Inspection Poseable Invertebrate Robot – was delivered to the International Space Station aboard the Automated Transfer Vehicle-5. Image Credit: NASA.

Longer-living spacecraft would in turn translate into extended services for people on Earth who rely on these satellites for timely, accurate data. “Satellites are the unseen powerhouses that quietly generate and move the data we rely on every day of our lives: weather reports, satellite television, GPS and communications support," explained Reed.

The newly delivered RRM hardware, consisting of a task board and the VIPIR tool, joins two other pieces that were delivered to space station in August 2013 by a Japanese cargo vehicle. The space station crew will stow these new RRM components inside the orbiting research center until the team can use Dextre to transfer and install them robotically on the RRM module. This transfer and the subsequent RRM-Phase 2 operations are being scheduled.